Starting from tegra3, the LP2 is no longer an appropriate name
for a particular CPU power state. LP2 on CPU0 means rail-gating,
LP2 on slave CPUs means power-gating. Starting from tegra11x,
even CPU0 can do power gating.

This changes function names to reflect the fact that the rail-gating
is a cluster-wide power state, and power gating is a per-CPU core
power state.